Nexus 4 (aka mako) has already received the official Android 5.1.1 Lollipop update from Google, while power-users who crave superior performance on their smartphone can go ahead and install the Android Open Source Project (AOSP) based CyanogenMod 12.1 (CM12.1) Nightly ROM with a host of built-in system optimisation tweaks and mods.

The CM12.1 ROM brings a lot of performance improvements and feature enhancements over stock ROMs released by OEMs and mobile-carriers such as Google, Samsung, Sony, HTC, T-Mobile and Sprint.

Interested users can go ahead and install the latest Android 5.1.1 based CM12.1 Nightly ROM on their Nexus 4, using the step-by-step guide provided below.

IBTimes UK reminds readers it will not be held liable for any damage to device during or after Lollipop firmware installation. Users are advised to proceed at their own risk.

Pre-requisites

The instructions given in this guide are meant for the international variant of Nexus 4 aka mako only. Verify device model number by navigating to Settings > About Phone

Ensure the phone has at least 80% battery charge to prevent unexpected device shutdown (due to battery drain) while installing the ROM

Back up data and settings using a recommended custom recovery tool, like ClockworkMod (CWM) or TWRP, as it creates a complete image of the existing phone setup. In Recovery, choose Backup and Restore and tap Backup

Verify correct USB drivers for the phone are installed on the computer

Step 4 - Power off the phone and disconnect its USB cable from computer

Step 5 - Boot the device into Bootloader Mode by pressing and holding Volume Up, Volume Down and Power buttons together

Step 6 - Once the phone enters into Bootloader mode, select CWM Recovery and perform a full data wipe task by clicking Wipe Data/Factory Reset. Use the Volume keys to navigate between options and Power button to select an option in the Recovery Mode

Step 8 - Perform Wipe Dalvik Cache as well. To do this, go to 'advanced' option and then click Wipe Dalvik Cache. This will help in preventing boot loop issues or any boot ROM related errors during firmware installation

Step 9 - Then return to the main recovery menu and choose Install Zip from SD card

Step 10 - Click Choose Zip from SD card. Use volume keys to navigate to the AOSP ROM zip file that you copied earlier to your phone's SD card and choose it by tapping the Power button. Confirm the ROM installation on next screen and the installation process will begin